In principle, the subject matter is a transport container system whereof the basic component is first of all a container that has a base, a casing and a lid. A container of this kind may be cubic or cuboid in form. In that case, the casing has longitudinal walls and transverse walls. The container may also be cylindrical or tubular in form. In that case, the casing has a cylindrical shape. The casing may be made in one piece with the base. The essential point is that at least one lid is present so that the interior of the container is accessible from the outside. A lid, in this context, may also be a laterally arranged door if, instead of a trough-like container that is upwardly closed by a lid, it is a cabinet-like container that is forwardly closed by a door.
The transport container system includes at least one container and an appropriate number of inner wall elements. However, it is also possible for a transport container system to include a plurality of containers having a correspondingly greater number of inner wall elements. In the case of a plurality of containers, the containers may have the same size and shape as one another or have different sizes and/or shapes.
A transport container system having a corresponding thermally insulated container is known from WO 2004/104498 A2. In this case, the container takes the form of a cabinet having an outer container, made from sheet metal or plate-like plastics material, and an inner container that is fitted inside the outer container. The inner container is formed by inner container wall elements that take the form of thermal insulation elements. All these inner container wall elements are in this case vacuum insulation panels. These are the thermal insulation elements with the best performance at present. We may refer the reader specifically to the content disclosed in this specification, which is a prior publication, and from which many aspects of transport containers of the type in question become apparent.
The transport container that is known from the prior art discussed above has a plurality of insert guides in the interior. A number, suitable for the intended purpose, of cooling packs or latent heat storage elements may be inserted into the insert guides. To this extent too, we may refer the reader to the content disclosed in this citation.
A latent heat storage element is based on the utilization of latent heat storage material. A latent heat storage material has the advantage that it can be used to store relatively large quantities of heat with a small temperature difference. Since the phase transition takes place at substantially constant temperature over a certain time span, it is possible to equalize temperature fluctuations and avoid temperature peaks.
Latent heat storage materials are known in various forms. These materials are also called PCM materials (from the English term “phase change material”).
If a target temperature (temperature of the phase transition) is around 0° C., water having different additives may be used as latent heat storage material. For cold storage below 0° C., suitably prepared salt solutions for example may be used.
In the range just above 0° C., other materials, such as those based on paraffin, are more suitable.
As background, the reader is specifically referred to the overview article from the BINE Information Service, “Themeninfo IV/02 aus dem Jahre 2002 [Focus IV/02 from 2002]”, (Fachinformationszentrum Karlsruhe, project identifier 0329840A-D, available at www.bine.info, search term “Latentwärmespeicher”). The reader is hereby referred to the content of this literature reference for a general background in latent heat storage materials and their possible uses.
A latent heat storage element according to the present invention is a latent heat storage material in a closed sheathing, where appropriate provided with a pressure equalization valve. This is also called a macro-encapsulated PCM material. The sheathing is frequently made from plastics material. The basic construction of, for example, so-called cooling packs is known.
Latent heat storage elements of this kind may be considered individually or also as a plurality of latent heat storage elements, incorporated for example into an appropriate container.
Latent heat storage elements of the type in question are now available for a wide range of target temperatures, including those from the applicant (brochure “va-Q-tec Packaging Portfolio, January 2011”). This provides latent heat storage elements for target temperatures of 37° C., 22° C., 4° C., 0° C., −19° C., −21° C. and −32° C. Other suppliers have comparable latent heat storage elements in their sales range, in some cases also for other target temperatures.
Latent heat storage elements of the type in question are used in the present field of application in thermally insulated containers, in particular for transport purposes. For example, this is applicable to the transport of temperature-sensitive products such as pharmaceuticals, bioengineering products, test equipment or samples for and from clinical studies, transplant materials or blood reserves. In this field of application, the optimum transport and storage temperature, which it is imperative to observe, is for example 2° C. to 8° C. Frequently, the products are only stable at all within a very narrow temperature range. For this reason, it is absolutely essential for these products to be transported and stored in this temperature range. Frequently, products of this kind, which are very sensitive to temperature in transport, must moreover on no account be allowed to freeze. In that case, temperatures below 0° C. must be reliably prevented.
In the case of the thermally insulated container discussed at the outset (WO 2004/104498 A2), the construction of the inner container and the arrangement of the individual inner container wall elements is fixedly predetermined from the outset. All the inner container wall elements are of like construction, preferably being vacuum insulation panels. If and to the extent that an individual inner container wall element can be removed and inserted, it is replaced by an inner container wall element of the same construction. This happens for example if a vacuum insulation panel is damaged.
In the known transport container system, the number of latent heat storage elements in the insert guides that are arranged on the inner faces on the inside of the inner container is variable. Different thermal requirements for the transported product may be taken into account by a larger or smaller number of latent heat storage elements in the transport container.
The above-described prior art relates to a transport container for temperature-sensitive transported product but not to a transport container system in the stricter sense.
By contrast, a transport container system of the type in question is known from DE 203 01 839 U1, which forms the starting point for the teaching of the present invention. The transport container system there has a container with an outer container that is made from thermally insulating material and an inner container that is made entirely from vacuum insulation panels. For a cuboid container, in that case six plate-like vacuum insulation panels are required for forming the inner container (on the base, on the four side walls and on the lid).
The prior art that is discussed above takes as a starting point the fact that there are provided on the walls of the container, preferably on all the inner faces, inner wall elements that may be removed from the container and inserted into the container, wherein each inner wall element has predetermined dimensions that are adapted to the associated inner face of the container. The concept of the known prior art is for only the inner wall elements on the two largest faces to take the form of vacuum insulation panels, whereas the inner wall elements on the four shorter lateral faces are equipped with thermally insulating elements of classic construction, for example made from conventional foam plastic.
The flexibility of the arrangement in this prior art is improved in that, instead of the inner container wall elements in the form of vacuum insulation panels, inner container wall elements in the form of cooling packs or heat retaining packs and of the same dimensions may be used.
In practice, it has been found that transport containers of the type in question must be set up for different thermal requirements, according to the actual use. In particular, the desired service period, that is to say the time for which the target temperature is maintained in the interior of the transport container intended to receive the transported product (conservation period), may also differ widely.
The teaching is thus based on the problem of constructing and further developing the transport container system of the type in question such that it may be adapted to different thermal requirements more flexibly than hitherto.
Finally, the teaching is also based on the problem of providing a correspondingly improved method for equipping a container of a transport container system of this kind.